Everglades Gets 6,000 Acres of Filter Marshes

Leftover sugarcane stalks floating through dark waters and clumps of cattails illustrates decades of damage and a gradual path to recovery for the pollution-choked Everglades.

Water managers and environmentalists recently gathered in southwestern Palm Beach County, Fla., to recognize a key step toward recovery--the conversion of 6,000 acres of former farmland to manmade wetlands for filtering pollutants from Everglades-bound water.

Fertilizers infused with phosphorus wash off sugarcane and other agricultural fields, polluting the Everglades by overloading its waters with nutrients and fuel the growth of cattails. This squeezes out sawgrass and other habitats vital to preserving the ecosystem.

Newly expanded storm water treatment areas help decrease the infusion by capturing water flowing off agricultural land and using cattails and submerged plants as natural filters. Since 1994, Florida has invested $1.8 billion in buying land and building 52,000 acres of storm water treatment areas. An additional 8,000 acres of filter marshes are in the works.

"This is like a dream come true for the Everglades," said Eric Draper, director of conservation for Audubon of Florida. "Even as we are celebrating progress, let's not slow down."

Lowering phosphorus levels became law in 1994 with the passing of the Everglades Forever Act, which mandated the construction of storm water treatment areas. In 2004, Florida launched its Acceler8 program to fast-track Everglades cleanup work; the program incorporates storm water treatment area expansions and the construction of reservoirs.

The district tries to hold storm water for one or two weeks in the treatment areas, which lie along I-27. Water is kept just a couple feet deep, and it moves through cells planted with cattails, pondweed, naiad, chara and other vegetation. Filtered water is then pumped through canals and delivered to Everglades water conservation areas.

Water that comes in with 100 to 200 parts per billion (ppb) of phosphorous can sometimes leave with 15 to 50 ppb, according to Deborah Drum, the district's director of storm water treatment area management.

In addition to serving as filter marshes, treatment areas also provide habitats for fish, wading birds, alligators and the occassional deer.

Florida's ultimate phosphorus level goal for the Everglades is 10 ppb, and it will take more work to reach that point, said Draper. To complement the addition of more storm water storage and treatment areas, environmentalists have called for residents and farmers to keep fertilizers and other pollutants from washing off lawns and fields.

Source: South Florida Sun-Sentinel